Electronic components installed in communication devices such as mobile phones are required to be small in size and have good frequency characteristics. To obtain good frequency characteristics at high frequency, a duplexer is formed with an acoustic wave filter. For example, in Japanese Patent Application Publication No. 2012-89996, a ladder-type filter using a Film Bulk Acoustic Resonator (FBAR) is used for the duplexer. A Surface Acoustic Wave (SAW) filter, or a boundary acoustic wave filter may be used as the acoustic wave filter. To improve frequency characteristics, it is important to match the impedance between the duplexer and an antenna. A passive element such as an inductor is used as a matching element. To downsize the electronic component, the duplexer and the matching element may be mounted on a single substrate.
However, the impedance matching may be difficult due to a wiring in the substrate in the conventional techniques. When a large matching element is connected for impedance matching, the size reduction is difficult.